Alarmed by rising illegal drug consumption among young people, officials in one Mexican state are preparing to test students for illegal narcotics use. The program is unprecedented in Mexico, a major trans-shipment point for U.S.-bound drugs, as it focuses not on teenagers but on primary school students.

Officials in the central Mexican state of Zacatecas said, according to a recent study, that drug consumption among minors is up a staggering 50 percent over the last five years. Zacatecas government Secretary Arturo Nahle said aggressive action is needed to reverse the trend.

Mr. Nahle said it is evident that in Zacatecas there has been a significant increase in drug use, particularly among minors. He said this has caused parents to become alarmed and given rise to the need for a testing program.

Traditionally, Mexican anti-narcotics initiatives have focused on adolescents and young adults. But the Zacatecas program will target primary school students. State officials have said many children are exposed to illegal drugs long before they reach secondary school, and that early intervention is required if the pattern of substance abuse is to be broken. The officials said marijuana appears to be the drug of choice among young people. But they add that smoking marijuana can serve as a gateway to the consumption of even-more dangerous substances, such as cocaine, later on.

Even so, the Zacatecas program has left some parents baffled. Maribel Barbosa said the idea of subjecting seven- and eight-year-olds to drug tests is ridiculous.

Asked if she approves of screening Mexico's youngest students, Ms. Barbosa said definitely not. She said it strikes her as illogical to do this to a child in primary school.

But other parents, like Nidia Cordova, have said they will back any initiative that promises to protect their children from substance abuse. if students know they will be tested regularly, Ms. Cordova said, it will dissuade them from using drugs and drastically reduce the number of abuse cases.

The early intervention program has caught the attention of local human rights workers, who argue that primary school students are too young to comprehend the drug issue or how a positive test result could affect them for the rest of their lives. Civil liberties activists worry about youngsters falling onto possible government black lists, and say that all people - even children - have certain rights to privacy.

Officials in Zacatcas respond by stressing that no child will be screened without the approval of his or her parents, and that test results will remain confidential.